1988 evinrude 70 vro lower unit question

[fmrodrigue]

my 70 hp evinrude jumps out of reverse when reved up in the water but not on the trailer. I have checked the shifter cable and its ok. I can hold down the shifter mechanism on the motor (in the water) and it does better but when torqued up at full throttle reverse it still jumps out of gear against my force of holding it back manually. Someone told me it could be a linkage malfunction in the housing but I dont really know where to look for this. Any sugestions greatly appreciated.

 

[HighTrim]

Re: 1988 evinrude 70 vro lower unit question

I would first try disconnecting the linkage at the motor and shifting manually to isolate the 2.

If it still does it it could be your dog and gear. The lobes of the dog and gear are precisely machined with sharp angles. When these edges wear, it forces the lobes apart when rpms increase, jumping out of gear. This is mainly caused by improper shifting. You need to shift with a deliberate movement, snapping the unit into gear as quickly as possible.

It is not "revving" up is it, as in a spun prop hub is it?

 

[fmrodrigue]

Re: 1988 evinrude 70 vro lower unit question

disconected reverse cable and it still did it. forward gear runs great so prop isnt a problem. only does it when there is resistance to the motor from the water. runs in reverse fine in the water idling and up to about 1000 rpm then it jumps out of gear. would a clutch dog cause this problem only in reverse?

 

[fmrodrigue]

Re: 1988 evinrude 70 vro lower unit question

disconected reverse cable and it still did it. forward gear runs great so prop isnt a problem. only does it when there is resistance to the motor from the water. runs in reverse fine in the water idling and up to about 1000 rpm then it jumps out of gear. would a clutch dog cause this problem only in reverse?

 

[HighTrim]

Re: 1988 evinrude 70 vro lower unit question

I hope its not and someone jumps in with a solution. I dont want to be the one to tell you the price of the shifter and reverse gear.

"http://www.crowleymarine.com/brp_parts/diagrams/27508.cfm"

 

[fmrodrigue]

Re: 1988 evinrude 70 vro lower unit question

thanks for the web page to crowley marine. they have a great view of scmatics and price list